C / C++ / MFC

12-Sep-11 1:28

Hello, I'm trying to display a web page inside my own window.

I found a c++ example by chris becke on the net which is huge. I ported the code into my application but I can only get the web page to display when I run the project in visual c++.

Is there a more bare bone example that displays a web page inside a window ? or why does my program only work when I run it from visual c++ ?

I'm not of a great state of intelligence to understand all the com code needed to display a web page but with a little help I think I might understand..

thanks,

CPallini12-Sep-11 2:16

12-Sep-11 2:16

If you are using MFC then you may have a look at "Using MFC to Host a WebBrowser Control"[^] at MSDN.

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

[My articles]

doug2513-Sep-11 2:50

13-Sep-11 2:50

Thanks, but i'm not using MFC

krmed12-Sep-11 3:56

krmed

12-Sep-11 3:56

When you run an application from inside Visual Studio, the working directory is the directory containing the project files (.vcxproj, .sln). However when you run outside of VS, the working directory is the one containing the .exe file.

So if you are opening an html file with just a file name (e.g. open "MyTest.html") then that file must exist in the working directory. You should use full path names to avoid this problem. (You can use GetModuleFileName to find out the directory containing your exe).

Hope that helps.

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doug2513-Sep-11 2:59

13-Sep-11 2:59

I understand this, I have been using the full path and file name.

I need to convert the string to a BSTR, I'm assuming i'm doing it correctly because as I say, the program works but only shows a web page when I run it from visual studio.
here's how:

C++

 char url[MAX_PATH];
 // _getcwd(url, MAX_PATH);
  GetModuleFileName(InstanceHandle, url, MAX_PATH);
  std::string file = url;
  file = file.substr(0, file.find_last_of("\\"));
  file += "\\Help.html";
  //file = "Help.html";

// show that the path is correct
  MessageBox(NULL, file.c_str(), NULL, NULL);

   OLECHAR* oleChar = NULL;
    oleChar = (OLECHAR*)calloc(file.length(), sizeof(OLECHAR));
    MultiByteToWideChar(CP_ACP, MB_PRECOMPOSED, file.c_str(), -1, oleChar, sizeof(WCHAR)*file.length());

  vURL.bstrVal = SysAllocString(oleChar);

doug2513-Sep-11 11:18

Member function pionters in C++

13-Sep-11 11:18

I've got the program to work Smile | :)

! after some modifications. still not sure what the problem was but I think it had something to do with structure declarations I'd placed in a header file..

Erudite_Eric12-Sep-11 0:30

12-Sep-11 0:30

So I use a lot of function pointers in C, and wanted to add one to a C++ class (MFC).

So I start off with a typedef in my class:

typedef ULONG (MyClass::*MyFunc)(PULONG, PVOID);

The call back:

ULONG MyFunc(PULONG, PVOID);

Another func that takes the callback as a parameter:

ULONG SomeFunc(PULONG, MyFunc, PVOID);

I then write the implementaiton of SomeFunc:
ULONG MyClass::SomeFunc(PULONG pVal, MyFunc pProc, PVOID pOpt)
{
...
}

To call the callback from inside MyClass::SomeFunc() I had to use this syntax:

ULONG ret = (this->*pProc)(&x, NULL);

I couldn't just call (*pProc)(&x, NULL); I had to add the 'this->'.

What a crappy syntax. You dont have to call other member funcs with a 'this->' so why is it required for function pointers?

--edit--

Perhaps it would look better as: (*this.*pProc)(&x, NULL); Smile | :)

Nah, thats WAY to much direction...

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Nothing to say.

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C^hris L^osinger12-Sep-11 1:52

C^hris L^osinger

12-Sep-11 1:52

Fat__Eric wrote:
What a crappy syntax. You dont have to call other member funcs with a 'this->' so why is it required for function pointers?

probably because whoever designed C++ was kind enough to mandate an implicit this-> for member fns, because calling member fns is a very common situation, but didn't bother for member fn ptrs, because that's much less common.

you can just make a macro for that ugly syntax

Erudite_Eric12-Sep-11 2:09

12-Sep-11 2:09

Chris Losinger wrote:
probably because whoever designed C++ was kind enough to mandate an implicit
this-> for member fns

You dont need to specify 'this->' when calling member funcs, you just call them by name. Thats the point I am making.

Chris Losinger wrote:
fn ptrs, because that's much less common.

Used a lot in C though. A heck of a lot. Surprises me they werent better catered for in C++.

Chris Losinger wrote:
you can just make a macro for that ugly syntax

Yeah, it sure is a pigs arse. Smile | :)

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Nothing to say.

CPallini12-Sep-11 2:13

12-Sep-11 2:13

Fat__Eric wrote:
Used a lot in C though. A heck of a lot. Surprises me they werent better catered for in C++

Possibly because C++ doesn't encourage C-style programming.

Erudite_Eric12-Sep-11 2:33

12-Sep-11 2:33

Yet there are a lot of functions in the Win32 API that use call backs. Smile | :)

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Nothing to say.

MicroVirus12-Sep-11 3:08

MicroVirus

12-Sep-11 3:08

The Windows API is more C than it is C++.

Erudite_Eric12-Sep-11 3:09

12-Sep-11 3:09

Are you suggesting that C++ was designed to be incompatible with the win 32 API? Smile | :)

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Nothing to say.

MicroVirus12-Sep-11 8:29

MicroVirus

12-Sep-11 8:29

Well... since all my C++ Win32 programs seem to work, I guess that can't be it, right? Poke tongue | ;-P

enhzflep12-Sep-11 18:27

enhzflep

12-Sep-11 18:27

For that to be true, the win32 Api would have had to exist first. (it didn't)

CPallini12-Sep-11 3:19

12-Sep-11 3:19

Fat__Eric wrote:
Yet there are a lot of functions in the Win32 API that use call backs.

C++ wasn't designed to favour Win32 API integration, I guess. Anyway there you don't need this, in fact the wrappers for Win32 API callbacks are (usually) static C++ methods.

Erudite_Eric12-Sep-11 3:50

12-Sep-11 3:50

Yeah, and the calling back mechanism is of course in the win32 api so it is ignorant of C++.

Anyway, it strikes me as a particularly daft limitation to have to specify 'this->' when legally just (*proc) is valid (since C++ extends the C language).

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Nothing to say.

CPallini12-Sep-11 4:03

12-Sep-11 4:03

That wouldn't be a method call, that would be a function call (i.e. the syntax would be indistinguishable).

Erudite_Eric12-Sep-11 4:08

12-Sep-11 4:08

CPallini wrote:
That wouldn't be a method call, that would be a function call (i.e. the syntax
would be indistinguishable).

Are you saying it is the same as C? It isnt.

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Nothing to say.

CPallini12-Sep-11 4:25

12-Sep-11 4:25

Why not?

Erudite_Eric12-Sep-11 4:31